1. Field of the Invention
The present invention relates to a production method of an orthodontic bracket with a positioning guide, which is bonded and fixed on a tongue side surface and/or a cheek side surface of each tooth of a patient.
2. Description of the Conventional Art
In an orthodontic treatment, since a movement of a tooth changes greatly with a slight difference of an installing position of an orthodontic bracket, it is very important to install the orthodontic bracket at a proper position.
In order to more accurately determine an installing position of an orthodontic bracket, a method called an indirect method or an indirect bonding method has been performed. In the indirect bonding method, a dental technician predetermines the installing position of an orthodontic bracket on a dentition gypsum model reproducing a dentition of a patient, adjusts the installing position so as to accurately install the orthodontic bracket to a tooth of the patient, and then, the dental technician installs the orthodontic bracket to the tooth of the patient. However, even though the installing position is predetermined on the dentition gypsum model as mentioned above, the orthodontic bracket easily deviates from the proper position when the dental technician actually installs the orthodontic bracket to the tooth of the patient. Thus, it is difficult to reproduce the accurate installing position.
For example, Japanese Patent Application Laid-Open No. 11-99161 discloses a method to solve the aforementioned problem. This method includes the steps of positioning an orthodontic bracket to each of teeth of a dentition gypsum model of a patient, supplying an uncured resin to each tooth of the dentition gypsum model, and forming independently for every tooth, a independent resin core for installing bracket, in which an advance part and a core part are integrally formed, the advance part is filled between a tooth and a base of the bracket positioned at the tooth, and the core part extends from the advance part to a cut edge or an occlusal surface of the tooth. The method further includes the steps of taking-out the independent resin core for installing bracket, which is integrated with the bracket, from each tooth of the dentition gypsum model, installing and bonding the taken-out independent resin core for installing bracket to each corresponding tooth of the patient, and removing each of the independent resin core parts for installing the bracket.
According to this installing method, since the core part independently formed at each tooth has a shape matching the cut edge or occlusal surface of each tooth of the patient, the bracket can be installed to a proper position by only fitting the core part to each tooth of the patient so as to cover the tooth. However, in this method, since a thickness of the core part is thick in a degree similar to that of the advance part, each disused core part should be removed after having installed the bracket to each tooth to be treated of the patient. Thus, the method needs much time and work, and has a problem that the installing position easily deviates when removing the disused core parts. Further, if the core parts are not completely removed, a residual resin could damage the cut edges or the occlusal surfaces of teeth clenched at a time of occlusion. Furthermore, since a normal temperature polymerizing resin is used for forming the advance part and the core part, an operation time is limited. Thus, it is hard to form the independent resin core having a shape fitting to each tooth to be treated of the patient.